[U] If filename provided is empty it assumes no logging to file

logging.go

@@ -57,72 +57,105 @@ var (
 )
 
 func (l *logStream) Printf(format string, a ...interface{}) {
+
 	// describe(a)
 	if LogLevel < l.logLevel {
+
 		return
+
 	}
 
 	// if no specific logger is configured for this logstrea, write to stdout...
 	logMessage := fmt.Sprintf(format, a...)
+
 	// Caller(1) is one level up the call stack - 0 identifies the caller of
 	// Caller which is this function...
 	callingStr := "[Unknown calling function]"
+
 	_, fn, lineNum, callerValid := runtime.Caller(1)
+
 	if callerValid {
+
 		callingStr = fn + ":" + strconv.Itoa(lineNum)
+
 	}
 
 	if l.s == nil {
+
 		fmt.Print(callingStr, " ", logMessage)
+
 		return
+
 	}
 
 	l.s.Print(callingStr, " ", logMessage)
 	// Printf(format, a...)
+
 }
 
 func (l *logStream) init(m io.Writer, s string, ll int) {
+
 	l.s = log.New(m, s, log.Ldate|log.Ltime)
+
 	l.logLevel = ll
+
 }
 
 // function to parse string representation of log level into integer - if there
 // is no match of the string, it will return 0 which maps to error only
 // logging...perhaps this could be made more explicit
 func determineLogLevel(lstr string) (returnVal int, err error) {
-	lstrLowerCase := strings.ToLower(lstr)
+
 	var validLogLevel bool
+
+	lstrLowerCase := strings.ToLower(lstr)
+
 	if returnVal, validLogLevel = logLevelStringMap[lstrLowerCase]; validLogLevel == false {
+
 		err = errors.New("Invalid Log Level")
+
 	}
+
 	return
+
 }
 
 // InitLogger initializes the logging system
 func InitLogger(logFile string, logLevelStr string, logToConsole bool) (err error) {
 
+	var file *os.File
+	var writters []io.Writer
+
 	if LogLevel, err = determineLogLevel(logLevelStr); err != nil {
-		return
-	}
 
-	var file *os.File
+		log.Println("Unable to determine the log level:", logLevelStr, ":", err)
-	if file, err = os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666); err != nil {
+
 		return
+
 	}
 
-	var multi io.Writer
+	if logFile != "" {
+
+		if file, err = os.OpenFile(logFile, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666); err != nil {
+
+			log.Println("Failed to open log file:", logFile, ":", err)
+
+			return
 
-	if err != nil {
-		log.Println("Failed to open log file:", logFile, ":", err)
-		multi = io.MultiWriter(os.Stdout)
-	} else {
-		if logToConsole {
-			multi = io.MultiWriter(file, os.Stdout)
-		} else {
-			multi = io.MultiWriter(file)
 		}
+
+		writters = append(writters, file)
+
+	}
+
+	if logToConsole {
+
+		writters = append(writters, os.Stdout)
+
 	}
 
+	multi := io.MultiWriter(writters...)
+
 	Trace.init(multi, "   TRACE: ", TRACE)
 	Debug.init(multi, "  DEBUG: ", DEBUG)
 	Info.init(multi, "   INFO: ", INFO)
@@ -130,4 +163,5 @@ func InitLogger(logFile string, logLevelStr string, logToConsole bool) (err erro
 	Error.init(multi, "  ERROR: ", ERROR)
 
 	return
+
 }